The second member of Xujiahe formation is the main gas producing interval of Pingluoba gas field. The pay is a tight fracture pore type reservoir composed of fine grained,fine to medium grained or medium grained feldespathic quartz sandstone and feldspathic lithic sandstone,with a burial depth of 3 400～3 900 m.

In the 4th block of the middle of Junggar Basin, the reservoir li-thology consists of feldspathic lith - arenite and lithic sandstones with lower compositional maturity, higher content of plastic lithic, and the diagenesis is in the A substage of late diagenesis period.

The result shows that the reservoir sandstone bodies can be divided into three types: that braid river delta, fan delta and shore-shallow lake. Reservoir rocks are primarily litharenite and feldspathic litharenite. Intergranular solution pores are the chiefly spaces for oil-gas accumulation.

The dinosaur fauna at Dashanpu is found in lower Shaximiao Formationof middle Jurassic, which consists of a suite of terrigenous clastic sediments.composed mainly by purple mudstone with greyish--green, medium--to micro-grained sandstone and siltstone intercalation. The compositional and texturalmaturity of sandstone is not high. The characteristics of paleontology andpetrology show that the lower Shaximiao Formation belongs to alternatedeposits of fluvial and lacustrine facies. The dinosaur fauna occurs in...

The dinosaur fauna at Dashanpu is found in lower Shaximiao Formationof middle Jurassic, which consists of a suite of terrigenous clastic sediments.composed mainly by purple mudstone with greyish--green, medium--to micro-grained sandstone and siltstone intercalation. The compositional and texturalmaturity of sandstone is not high. The characteristics of paleontology andpetrology show that the lower Shaximiao Formation belongs to alternatedeposits of fluvial and lacustrine facies. The dinosaur fauna occurs in micro--grained feldspatholithic sandstone,which is rich in mica fragments, matrix interstitial. Wave--ripple crossbedding, micro--wavy bedding and medium--to large--scale tabular crossbedding are clearly seen. Petrological characteristics indicate that it belongsto lake--shore shallow--bank deposit under lower energy condition. At that time, the dinosaurs lived on a lake--shore plain with profusewater and grass. The reason for leading them to a mass death is supposed tobe poisoning by plants with abundant arsenic the dinosaurs ate. Their remainswere buried in the lake--shore shallow--bank. The abnormal death and theburial in situ in shallow--bank of low energy are the main factors to providea great deal of well preserved dinosaur fossils in this region.

Fuyu Oil Play belongs to the 4th Member ( K1q4 ) of Quantou Formation, Songhuajiang River Group of Cretaceous. It is one of the major plays in the southern Songliao Basin, After the examination on numerous thin sec-tions of rocks, the following understandings on the diagenesis of the oil play have been achieved.

The sandstone in Xuer section was mainly dominated by micropores. There were fewer feldspar and detritus solution pores and rare or no carbonate solution pores. This phenomenon has been explained by the steady carbon isotope of calcite and thermodynamics theory. The samples, the porosity of which is over 5%, must contain chlorite coatings and display high water saturation as well as low electric resistvity, which leads to mismisjudging gas an water layer. Detailed petrology researches show that clay minerals...

The sandstone in Xuer section was mainly dominated by micropores. There were fewer feldspar and detritus solution pores and rare or no carbonate solution pores. This phenomenon has been explained by the steady carbon isotope of calcite and thermodynamics theory. The samples, the porosity of which is over 5%, must contain chlorite coatings and display high water saturation as well as low electric resistvity, which leads to mismisjudging gas an water layer. Detailed petrology researches show that clay minerals play a particular role in the process of diagenesis. The storage capacity of samples with clay is better than that with carbonates. A new concept of "pore life-span" is proposed and its significance in petroleum exploration is discussed in this paper.